You're right, Tolkien was certainly thinking of works like the Völsunga, along with various other sources!

But look at the names: Ungoliant, Amon Amarth, Fingolfin, Tol-in-Gaurhoth! His abilities as a linguist and student of comparative folklore really shine in his names. Each of them encompasses an essence, a history, a character.

If you're interested in this sort of thing (modern attempts at fictional cosmogonies and creation myths) Dunsany's Gods of Pegana is another seminal work. What it lacks in Tolkien's meticulousness and painstaking, life-long development, it makes up for in sheer power of imagination and entertainment.